1. Field of the Invention
The present invention relates to an occupant protecting structure of a vehicle body upper portion, and particularly to an occupant protecting structure of a vehicle body upper portion, which is applied to at least one of a pillar and a roof rail.
2. Description of the Related Art
Conventionally, there has been known, as an occupant protecting structure of a vehicle body upper portion, a structure in which an inner side of a pillar and/or an inner side of a roof rail in a transverse direction of a vehicle are/is covered with a garnish made of resin material. With this structure, generally, a closed cross-sectional configuration is formed by connecting an outer panel and an inner panel of the pillar and/or the roof rail, and the pillar and/or the roof rail have/has a large rigidity and strength. Accordingly, from a viewpoint of protecting an occupant from a vehicle to improve safety of an inner panel having a large rigidity and strength.
There is disclosed in Japanese Patent Application Laid-Open No. 6-211161, a high-safety occupant protecting structure of a vehicle body upper portion of a roof rail.
As shown in FIG. 17, a roof rail 70 includes a roof outer panel 72, a thin-walled roof inner panel 74, a roof reinforce 76, and a honeycomb-structural body 78. The roof reinforce 76 is disposed between respective joint portions of the roof inner panel 74 and the roof outer panel 72 so as to divide a closed cross-sectional area of the roof rail 70 into two sections of an interior side and an exterior side of a vehicle. The honeycomb-structural body 78 for preventing deterioration of rigidity of the roof inner panel 74 is disposed within a closed cross-sectional area between the roof reinforce 76 and the roof inner panel 74 and is provided along the same direction as that in which the closed cross-sectional area between the roof reinforce 76 and the roof inner panel 74 is disposed. With this structure, when an occupant's head portion collides against the roof rail 70 by a collision in a lateral direction, the root inner panel 74 easily deforms so that the honeycomb-structural body 78 for preventing deterioration of rigidity of the roof inner panel 74 is easily crushed.
However, since the honeycomb-structural body 78 is an essential component in this structure, a cost of the honeycomb-structural body 78 and a process of building-in the honeycomb-structural body are required.
Further, another example of the occupant protecting structure of the vehicle body upper portion is disclosed in Japanese Patent Application Laid-Open No. 4-125953.
As shown in FIG. 18, with this structure disclosed therein, a garnish 84 for covering an inner panel 82 of a center pillar 80 is formed hollow by a back wall 84A serving as a surface to be mounted on the inner panel 82 and a front wall 84B separated from the back wall 84A, and a front-wall receiving portion 84C having a semicircular cross-sectional configuration and projecting toward the front wall 84B is formed along a vertical direction and integrally formed with the back wall 84A at a central portion thereof in a longitudinal direction of the vehicle. When external force is applied to the front wall 84B of the garnish 84 due to an occupant colliding against the garnish 84, the front wall 84B flexibly deforms and,.contacts the front-wall receiving portion 84C with pressure, so that compressive load acts on the front-wall receiving portion 84C. This compressive load is dispersed in a circumferential direction of the front-wall receiving portion 84C due to the semicircular cross-sectional configuration thereof. For this reason, localized deformation of the front-wall receiving portion 84C due to concentration of the load is prevented and the front-wall receiving portion 84C deforms entirely with its diameter enlarged. In this way, absorption of energy is attained by each elastic deformation of the front wall 84 and the front-wall receiving portion 84C and the whole elastic deformation of the hollow garnish 84.
However, since this structure is constructed such that absorption of energy is effected by the garnish 84 made of resin material, when considering changes in the resin material over time, there existed a drawback in that the shape of the garnish 84 becomes complicated as described above in order to obtain stabilized energy absorption characteristics for a long period of time.
Prior art of the present invention is also disclosed in Japanese Patent Application Laid-Open No. 6-239189, and U.S. Pat. Nos. 3,779,595, 5,163,730 and 5,382,051.